Circuit arrangement for automatic telephone systems



May 28, 1929. LANGER 1,714,881

CIRCUIT ARRANGEMENT FOR AUTOMATIC TELEPHONE SYSTEMS Filed July 5, 1927 2 Sheets-Sheet l ff-f Inuanlur P'Iax Lan er May 28, 1929. LANGER 1,714,881

CIRCUIT ARRANGEMENT FOR AUTOMATIC TELEPHONE SYSTEMS Filed July 5, 1927 2 Sheets-Sheet 2 v r 0 I 8 8340000070? 0.00000? loeoooooozil 4m} g r/ j wane 5 r Ani/ R1 R1 IH G iii M Patented May 28, 1929.

UNITED STATES PATENT OFFICE.

MAX LANG-ER, F BERLIN, GERMANY, ASSIGNOR T0 SIEMENS & HALSKE AKTIEN- GESELLSCHAFT, WERNERWERK, 0F SIEMENSTADT' NEAR BERLIN, GERMANY.

CIRCUIT ARRANGEMENT FOR AUTOMATIC TELEPHOIIE SYSTEMS.

Application filed July 5, 1927, Serial No. 203,322, and in Germany July 13, 1926'.

The invention relates to automatic tele-' and existence of a connection, are effected over one signalling line common to several junction lines.

In the known arrangements of this kind the calling station receives the busy signal when all signalling lines are engaged, or with semi-automatic working the operator is given no exchange signal, so that the impulse transmission has to be delayed until a signal line is free, thereb considerably delaying the setting up of t e connection, especially when the junction line trafiic is dense.

Now the object of the present invention is to speed up the traflic, this being rendered possible by providing an impulse storer at the outgoing end of the signalling line.

When the signal line is engaged, the storer accepts the current impulses transmitted from the calling station and transmits them to the receiving devices at the incoming end of the signalling line when the latter becomes free.

The invention is illustrated by way of example in the drawing, which shows an arrangement for semi-automatic working over a trunk line.

For the purpose of describing the method of working this arrangement, it will first be assumed that the signalling line is free. When the number of the wanted subscriber has been communicated to the operator in known manner, she inserts the calling plug into the jack VK 1 of an idle junction line and inserts the plug 1 into the switch jack WK 1. The following sleeve circuit is then established: battery, resistance Wi, sleeve of the jack VVK'l, contact 1', winding of the relay 1V, contact 0 at the third contact set of the switch WI, winding of relay An 1, contact t 1, earth. Relay W is operated, at its contacts w 1, w 2 it applies the exchange signal to the speaking leads. Relay An 1 is likewise energized and switches over its contacts. At contact 1 an 1 it closes its own locking circuit and at contact 3 an 1 it opens the signalling lead. At contact 2 an 1 the relay interrupter RU is connected up, which alternately opens and closes a circuit for the relay F. In response to these interruptions, the relay F 1 is energized and de-energized and at the same time its contact 7 1 closes and opens the circuit for the rotary magnet \D I of the switch W I. The rotary magnet moves on the wipers of the switch W I until they reach the line leads a and 6 taken into use by the operator.

At the incoming end of the signalling line the wlpers of the switch W II are moved on synchronously with those of the switch W I. At the same time intervals as for the rotary magnet D I, the relay F closes and opens the circuit for the rotary magnet D II over: earth, contact f 2, winding of the rotary magnet D II, battery, earth.

The circuit of both the rotary magnets is finally opened as soon as the wipers of the switch W I reach the leads a and b. The relays R and T are then operated over battery, resistance We, bush of the jack WK 1, WlIldlIlg of relay R, lead b, corresponding contact at the second contact set of the switch W I, windings I and II ofthe relay T, earth. Relay T at its contact If 1 interrupts the circuit of the relay An 1, which falls back and at contact 3 am 1 again switches through the signalling lead w '1. At the contact 2 an 1 the relay interrupter is disconnected from the relay F, so that it can operate no more, and at contact 7 1 it permanently opens the circuit of the rotary magnet D I and at contact 7- 2 that of the rotary magnet D II. The relay T at its contact If 2 short circuits its high resistance winding and prevents the signalling line being taken into use over a line connected in multiple at the same contact of the switch. On being operated over the above described circuit, the relay R at its contact r opens the circuit for the relay W, which falls back and at its contacts 'w 1 and w 2 disconnects the exchange signal from the speaking leads. This notifies the operator that she can dial.

During the return motion of the number dial, a circuit is closed and opened for the impulse repeating relay J at the incoming end of the signaling line a number of times corresponding to the selected number: earth, impulse contact 2', jack W701, lead a, contact and wiper of the switch W I 1, back contact 3 an 1, wiper and contact of the switch W II, winding of relay J, battery, earth. The relay J is alternately energized and deenergized. At the first impulse of current its contact 1 2 closes a circuit for energizing the relay V, which at its contacts 0 1 and o 2 prepares the impulse loop to the impulse receiving relay at the succeeding connecting devices, and as the relay is slow to release, it holds up during the train of impulses. At each impulse the contact i 1 closes and opens the loop. The circuit for this loop extends over: earth, impulse contact 71 1, front contact 1) 1, a-lead, b-lead, front contact v 2, resistance W2, battery,'earth. Another impulse contact 6 3 closes the following circuit for energizing the relay C: earth, impulse contactz' 3, back contact a 2, winding of relay 0, back contacts e 1 and i 3, resistance W71, battery, earth. The relay G at contact 0 2 closes its locking circuit and at contact 0 3 it energizes the relay E by removing its short circuit: earth, front contact c 2, winding of relay C, winding of relay E, resistance We, battery, earth. At contact a 1 is earthed the test lead to the succeeding connecting devices.

The selection having been ended, the relay V" falls back and at its contacts 1; 1 and Q) 2 it switches through the speaking leads. When the operator at the called trunk exchange or the called subscriber answers, the operator at the local exchange withdraws the plug 1 from the switch jack. Instead of removing the plug, the sleeve circuit could be interrupted by means of a key. Thus the relays R and T are released. The relay An 1 is operated over earth, back contact t 1, winding of relay An 1, wiper and contact of the switch W I 3, resistance W2, battery, earth. At its contact 2 an 1 the relay connects up the relay interrupter. The relay F is alternately energized and de-energized and it operates the rotary magnet D I over its contact 7 2. The wipers of the switches WI and W II are moved on until the 0 position is reached. The. circuit for the relay An 1 is then interrupted and the switches remain in their normal position. The devices of the signalling line have now returned to their normal posit-ion, hence they can be used for establishing another connection.

At the end of the conversation the operator again closes the sleeve circuit. In the manner above described, the switches again go into the position designated by the contacts, to which the leads a and b are connected. The exchange signal having ceased, the operator actuates the release key,

thereby giving a longer releasing current impulse to the connecting devices at the incoming end of the signalling line. Over the contact 6 3 the relay G is short circuited and released so that earth is disconnected from the test lead. At contact 0 2 is interrupted the locking circuit for the relays C and E. At the end of the release current impulse, the relay E also falls back, thus these devices have been returned to their normal position. The operator now withdraws the plug 1 from the switch jack and this causes the relay T to fall back. The switches then go into theirnormal position, hence all the devices are in their normal position after the operator has withdrawn the calling plug from the connecting jack VK 1.

It will now be assumed that all the sig nalling lines associated with the particular junction line are engaged. In that case the operator performs the same operations as those already described. She receives the exchange signal when she inserts the plug 1 into the switch jack. The relay W is now operated over the following circuit: battery, resistance Wz', sleeve of the jack WK 1, back contact 7', winding of relay W, back contact 9, contact 0 at the third contact set of the switch W III, winding of relay An 2, back contact a 5, earth. The relay W at its contacts w 1 and w 2 connects the exchange signal to the speaking leads. The relay An 2 is likewise energized; it closes the locking circuit for itself at contact 4 an 2 and at contact 3 an 2 it connects the relay interrupter RU 1 to the rotary magnet D III of the switch W III. The rotary magnet moves on the wipers of the switch until they reach the contacts, to which the leads a and b are connected. The following circuit is then established: battery, resistance W2, sleeve of the jack WK 1, winding of relay R, lead I), contact and wiper of switch W III, back contacts 1) and 0 1, windings I and II of the relay U, earth.- In this circuit the'relays R and U are operated. The relay R interrupts the circuit of relay W, which at its contacts w 1 and w 2 discon nects the exchange signal from the speaking leads. By opening its contact, the relay R also prevents the leads a. and b being connected to a signalling line that becomes free during the selecting operation, as this would cause the incomplete transmission of current impulses. The relay U at its contact 10 5 interrupts the circuit of the relay An 2, which disconnects the interrupter RU 1 from the rotary magnet D III. The switch W III therefore remains standing on the contacts designated by the leads a and b. At contact u 1 the high resistance winding of the relay U is short circuited and the storer is prevented from being taken into use by another party. At the contact 2 0m, 2-the circuit for the rotary magnet D V is prepared to receive number impulses and at contact a 3 a circuit is prepared for the relay B.

If the operator now dials, this circuit is alternately closed and opened for the rotary magnet during the return of number dial. The circuit extends from earth over the impulse contact i, jack WK 1, lead a, corresponding contact and wiper at the second contact set of the switch W III, back concircuit for the relay C, and at contact contact t 1, earth.

rotary magnet D V to battery, earth. The rotary magnet D V moves on the wipers of the switch 1V V. The circuit of relay B is closed at the first impulse. The relay falls back slowly and holds up during the train of impulses. At the'end of the first train of impulses, the relay B falls back and at its contact I) it closes the following circuit for energizing the relay V: earth, back contact I), wiper and contact at the second set of contacts of the switch \V V, winding of relay V, battery, earth. The relay V actuates its contacts and at change over contact 5" it switches the circuit for the number impulses to be received over to the rotary magnet D VI. At contact 5' is closed a circuit for keeping energized the second winding of relay V, this circuit having been prepared by the relay C I. \Vhen the relay U was operated, the relay C I was energized over: earth, front contact a 4, back contact 8, winding of relay C I, battery, earth. During the return motion of the number dial, the current impulses are transmitted to the rotary magnet D VI, which moves on the wipers of the switch IV VI a number of times corresponding to the number dialled. In the same manner as that described above,

the third train of impulses is transmitted to the rotary magnet D VII.

All the trains of impulses having been stored up, the relay VII is operated; at. contact 7 it closes the locking circuit for its winding II, at contact 7 it closes a locking 7 it prepares a circuit for the relay 0. The dialling having been completed, the operator withdraws the plug 1 from the jack \V k1, thereby disconnecting the relay U, which switches over its contacts.

Vhen a signalling line becomes free, the relay T falls back and the switches V I and \V II move into their normal position. At contact 25.3 is closed a circuit for energizing the relay G, which at its contact closes the following circuit for the relays O and An 1: battery, back contacts .3 2 and u 2, front contact 7 winding of relay 0, front contact 9, contact 0 at the third contact set of the switch \V I, winding of relay An; 1, back The relay An 1 at its contact 1 an. 1 closes a locking circuit for itself and for the relay 0 and in the manner described above it actuates the rotary magnet D I. lVhen the wipers of the switch reach the contacts, to which the leads a and b are connected, the relays T and P are operated in the following route: earth, windings I and II of the relay T, wiper and contact at the second contact set of the switch IV I, contact and wiper of the first contact remains open.

An 1 and O and at contact 253 it interrupts the circuit of relay G. Relay An 1 at its that of the rotary magnet D I. Relay 1 at its contact p closes a locking circuit for itself and at contact ;0 1 it closes a circuit for energizing the impulse relay J 1: battery, back contacts 8 2, u 2, front contacts 7" and p 1, winding of relay J 1, earth. Relay J 1 at its contact 11 I 1 closes the circuit of the rotary magnet D IV, which moves on its wipers one step and at contact d 4 short circuits the relay J 1. The latter therefore falls back and at contact a I 1 it opens the circuit of the rotary magnet, which removes the short circuit from the relayJ 1. In this manner the relay J 1 and the rotary magnet D IV are alternately energized and deenergizcd. The rotary magnet moves the switch wipers of the switch W IV step by step. From the second step onwards of the switch W IV' the circuit of the relay J 1 extends over: earth, winding of relay J 1, wiper and bank contacts 1-10 of the switch W IV, resistance We, battery, earth. The relay J 1 at its contact 6 I 3 closes and opens a circuit for the impulse repeating relay J at the incoming end of-the signalling line: earth, back contact 0, impulse contact 71 I 3, back contact r I 1, front contaetp 2, back contact 2 an 2, Wiper and bank contact of the switch V 'III 2, wiper and contact of the switch W I 1, back contact 3 am 1, signalling line a 1, wiper and contact of theswitch l/V II, winding of relay J, battery, earth. This circuit is kept open when the second wiper of the switch W IV reaches the contact designated by the Wiper of the switch W V. Thereupon a circuit for the relay R 1 is prepared, which is closed'upon the release of the relay J 1: earth, impulse contact 71 I 2, winding I of the relay R 1, second wiper and contact of the switch W IV, marked contact and wiper of the contact set 1 of the switch IN V, battery, earth. Relay R 1 is operated and at contact 9" I 1 it permanently opens the circuit to the impulse repeating relay J. A locking circuit for the second winding of relay R 1 is closed at contact z 15, hence the impulse circuit Only on the switch W IV reaching the eleventh contact do es the relay R release its armature, because then the following circuit is closed for the opposing winding III of the relay R 1 I: earth, impulse contact i I 2, winding I of relay R 1, wiper and contact 11 of the switch IV IV, front contact 1 I, opposing winding III of relay R 1, battery, earth. Contact 11 is a stopping contact. The slow acting relay Q was also energized over the second winding of'the relay R 1, and at contact 9 1 it interrupts the circuit of the impulse relay J 1 over the eleventh contact. Now when the opposing winding III of relay R 1 is connected up, the relay Q also falls back, and as it is slow to release, the circuit of the relay J 1 remains open for some time. The stopping place is inserted for the purpose of giving time for the switching over of the connecting devices, which at the incoming end of the junction line are positioned by current impulses. After the relay Q has fallen back, the circuit of the impulse relay J 1 is closed again and the second train of impulses is sent to the impulse repeating relay J at the incoming end of the signalling line in the same manner as that described above. Contact 23 likewise forms a stopping place.

The last train of impulses have the same effect on the connecting devices at the incoming end of the signalling line as that described above. After this train has been transmitted, the speaking leads are switched through from the called to the calling subscriber and the conversation can be carried on. At the contact 35 of the switch W IV a circuit is then closed for the first winding of relay S, which is slow to release: earth, impulse contact 71 I 2, winding I of relay R, wiper and contact 35 of the switch W IV, winding I of relay S, battery, earth. Relay S at its contact 8 opens the circuit of the relay C I. Relay C I falls back and its contact 0 I' 4 opens the locking circuit of the second windings of the relays V, VI and VII. At contact 0 I 3 the following circuit is closed for the relay An 2: earth, back contact u 5, winding of relay An 2, wiper and contact at the third contact set of the switch W III, back contact a I 3, winding I of relay S, battery, earth. 'Relay An 2 is operated and it connects the relay interrupter RU 1 to the rotary magnet D III. The rotary magnet moves on the wipers of the switch W III until the normal position is reached. The circuit of the relay An 2 is then interrupted and the switch remains standing in. its normal position. At contact c I 2 the relay interrupter is connected to the rotary magnet D VII of the switch W VII: earth, relay interrupter EU 1, winding II of the relay S, back contact 0 I 2, wiper and contact of the switch W VII 3, winding of the rotary magnet D VII, battery, earth. The rotary magnet D VII is alternately energized and de-energized, and moves on the wipers of the switch W VII until they reach-the normal osit-ion.

Thereupon is opened the circuit 0 the rotary magnet D VII and of the winding I of the relay VII. The relay VII moves its contact 7 into the normal position and con nects the relay interrupter to the rotary magnet D VI, which brings the wipers of the switch W VI into the normal position, wherein the circuit of the rotary magnet D VI and of the relay VI is interrupted.

At contact 6 of the relay VI the relay interrupter RU 1 is now switched over to the rotary magnet D V, which brings the wipers of the switch W V into the normal position. The circuit of the relay S is now interrupted. The above described moving on of the switch W III caused the circuit of the relay' T to be interrupted; the relay falls back and at its contact t1 it operates the relay An l-over: earth, back contact t 1, winding of relay An 1, wiper and contact bank of the third contact set of the switch W I, resistance W21, battery, earth. The contact of relay An 1 connects therelay interrupter to the relay F, which at its contact f 1 alternately energizes and de-energizes the rotary magnet D I and at contact 7' 2 alternately energizes and de-energizes the rotary magnet D II. The rotary magnets D I and D II move the wipers of the switches W I and W II as far as the normal position, wherein the circuit of the relay An 1 is interrupted. Now all the devices of the signalling line as well as the storer have returned to the normal position, so that both can be used for another connection. The

release of the other junction lines at the end of the conversation takes place in the same manner as that described above.

What is claimed is:

1. In a telephone system, a plurality of outgoing trunks each terminating at the distant end in an automatic switch, a plurality of control lines, means for seizing a trunk, an impulse transmitter, means for connecting the transmitter to an idle control line, an impulse storer, means effective if no control line is available for connecting the im pulse transmitter to the impulse storer, means efi'ective if the connection is to the impulse storer for connecting the impulse storer to a control line when one becomes available, means for connecting the'distant end of the control line connected with to the switch that terminates the seized trunk, means for operating the switch by digit inipulses transmitted over the control line, and means for disconnecting the control line from the switch to render the control line available for further use, without releasing the switch.

2. In a telephone system, a plurality of outgoing trunks each terminating at the distant end in an automatic switch, a plurality of control lines, means for seizing a trunk, an impulse transmitter, means for connecting the transmitter to an idle control line, an impulse storer, means effective if no idle control line is available for connecting the impulse transmitter to the impulse storer, means effective if the connection is to the impulse storer for connecting the impulse storer to an idle control. line when one becomes available, means for connecting the distant end of the control line connected with to the switch that terminates the seized trunk, means for transmitting digit impulses over the control line to operate the switch, means for disconnecting the control line from the switch to render the control line available for further use, Without releasing the switch, and means for connecting the line to a switch which is operated for releasing the switch.

3. In a telephone system, a plurality of outgoingtrunks each terminating at the distant end in an automatic switch, a control line common to said switches for controlling the switches, an impulse transmitter, an impulse storer, means for connecting the transmitter to the control line or to the impulse storer de ending upon the busy or idle condition o the control line, and means efi'ective if the connection is to the impulse storer for connecting the impulse storer to the control line when the control line becomes idle.

4. In a telephone system, a plurality of outgoing trunks each terminating at the distant end in an automatic switch, a control line common to said switches for controlling the switches, an impulse transmitter, an impulse storer, means for connecting the transmitter to the control line or to the impulse storer depending upon the busy or idle condition of the control line, means effective if the connection is to the impulse storer for connecting the impulse storer to the control line when the control line becomes idle, and means for preventing the impulse storer from being connected-to the control line, until a certain number of digits have been stored.

5. In automatic telephone system, a plurality of outgoing trunks each terminating at the distant end in an automatic switch, a control line common to said switches for controlling said switches, an impulse transmitter, an impulse storer, means responsive to the seizure of a trunk for connecting the transmitter to the control line or to the storer depending upon the busy or idle condition of the control line, means effective if the connection is to the storer for connecting the storer to the control. line when-the control line becomes idle, means for connecting the control line to the automatic switch terminating the seized trunk, and means for transmitting digit impulses over the control line from the transmitter or from the storer depending upon which is connected to the control line, for operating the switch terminating the seized trunk.

6. In a telephone system, a plurality of outgoing trunks each terminating at the distant end in an automatic switch, a control line common to said switches for controlling said switches, an impulse transmitter, an impulse storer, means responsive to the seizure of a trunk for connecting the transmitter to the control line or to the storer depending upon the busy or idle condition of the control line, means efiective if the connection is to the storer for connecting the storer to the control line when the control line becomes idle, means for connecting the'control line to the automatic switch terminating the seized trunk, means for transmitting digit impulses over the control line from the transmitter or from the storer depending upon which is connected to the control line, for operating the switch terminating the seized trunk, and means for disconnectm the control line from the automatic switc without releasing the switch for rendering the line available for further use.

7. In a telephone system, a plurality of outgoin trunks each terminatin at the distant end in an automatic switc a control line common to said switches for controlling said switches, an impulse transmitter, an impulse storer, means responsive to the seiz-' ure of a trunk for connecting the transmitter to the control line or to the storer depending upon the busy or idle condition of the control line, means effective if the connection is to the storer for connecting the storer to the control line when the control line becomes idle, means for connecting the control line to the automatic switch terminating the seized trunk, means for transmitting digit impulses over the control line from the transmitter or from the storer depending upon which is connected to the control line, for operating the switch terminating the seized trunk, means for disconnecting the control line from the automatic switch without releasing the switch, and means for connecting the line to a switch which is operated for releasing the switch.

8. In a telephone system, a plurality of trunks each terminatlng in an automatic switch at the distant end, a control line common to said switches, an impulse transmitter associated with one of the trunks, means for connecting the impulse transmitter to the control line, an impulse storer, means for connecting the impulse storer to the impulse transmitter when the control line is busy, means effective when. the control line becomes idle for connecting the storer to the control line, and means for operating the automatic switch that terminates the trunk with which the impulse transmitter was associated, by digit impulses transmitted over the control line.

9. In a telephone system wherein a common control line is automatically connected to a digit impulse transmitter, and upon the termination of the transmission of the digit impulses is released, the combination of an impulse storer, means eifective if the control line is busy when the impulse transmitter is taken into use for preventing the control line from being connected to the transmitter, and for connecting instead the impulse line, and means eflective when the impulses stored have been transmitted for releasing the connection.

10. In a telephone system, a switch which is operated by digit impulses and over which talking connections are established, an impulse transmitter, an impulse storer, means forsetting up an impulsing circuit from the transmitter to the switch or to the impulse storer depending upon the existence of predetermined conditions, and means effective if the connection is to the impulse storer for establishing an impuls'ing circuit\ from the storer to the switch for operating said switch upon the occurrence of predetermined conditions. I

11. In a telephone system, a switch which is operated by digit impulses and over which talking connections are established, an imulse transmitter, an impulse storer, means or setting up an impulsing circuit from the transmitter to the switch or to the impulse storer depending upon the existence of predetermined conditions, means efi'ective if the connection is to the impulse storer for establishing an impulsing circuit from the storer to the switch for operating said switch upon the occurrence of predetermined conditions, and means for preventing the establishment of the last named connection until a certain number of digits have been stored 12. In a telephone system, an impulse transmitter, a control line, an impulse storer, means for connecting the transmitter to the control line or to the storer depending upon predetermined conditions and means for indicating to a party at the transmitter the establishment of a connection regardless of those conditions.

13. In a telephone system, an impulse transmitter, a control line, an impulse storer, means for connecting the transmitter to the line if the line is idle and to the impulse storer if the line is busy.

14. In a telephone system, an impulse transmitter, a control line, an impulse storer, means for connecting the transmitter to the line if the line is idle and to the impulse storer if the line is busy to a party at the transmitter, and means for indicating alike to a party at the transmitter the establishment of either of the two connections.

15. In a telephone system, a plurality of trunks each terminating in a separate automatic switch, a control line common to said trunks, means effective when one of said trunks is taken into use for temporarily renering said control line individual to the trunk in use, an impulse transmitter, an impulse storer, and means including said transmitter or said storer for transmitting impulses over said control line to operate the switch associated with the trunk in use de pendent upon whether said transmitter or said storer is connected with said control 16. In a telephone system wherein a plurality of trunks terminate in automatic switches arranged to be controlled by impulses transmitted by an impulse transmitter and by impulses transmitted by a combined impulse storer and sender over a control line common to said trunks, means effective when a trunk is taken into use for connecting the control line with the trunk and transmitter in case the control line is idle, means effective in case the control line is busy for connecting the transmitter with the combined storer and. sender to temporarily store the impulses transmitted by the said transmitter, and means for connecting the combined storer and sender with the control line when the control line becomes idle.

In witness whereof, I hereunto subscribe my name this 30th day of May, A. D. 1927.

MAX LANGER, 

